Synthetic resins and process of preparing same



. Io Drawing.

Patented July 12 1932 UNITED srA ras A-rE'N-r-orrrce nuns :emnotrss, or 'WASHINGI'BN, 'msrmc'r or oonmni, assrenon 'ro mi A."

omm nanonaronr, me, or rename or m msrnror or wasnnqo ron, nrsrnrcr or CQLUIBIA conumnm, a consmmirro nnsms AND rnocnss or rmmne sum Application filed pay 17,

This invention relates to synthetic resins which combinethe properties of the pht-halicester and phenol-formaldehyde types of resins, and to methods of preparing the same.

his known that the phthalic acid esters high molecular weight,

of polyhydric alcohols, including glycol, glycerin, and the like,-especially when pre pared in the presence of carboxyic acids of possess valuable properties when used as reslns and plasticizers in the manufacture of nitrocellulose limquers. But the insolubility of these esters in vegetable oils limits their application in the preparation of oil varnishes. They are also not enerally compatible with cellulose acetate a'cquers. The phenol-formaldehyde resins, on the other hand, when fused with natural gums, such as, for example, rosin, are

rfectly solublein drying oils and are bemg used extensivelyin the manufacture of ql lnck drying oil varnishes. But the use of t is type of resin is very restricted in cellulose lacquers, on account of their odor, the

of the latter when, exposed brittleness of the resultin film, discoloration,

to atmospheric influences, limited compatibility, and other deficiencies. When certain'resinous composi duced they may form films which are very tions are used inmakingquick drying varnishes the resulting solutions some tlmes are hazy} or, if they are'clear when initially prohazy and cloudyupon drying. It. is to this phenomenon that, Irefer in the present dethe basis of the scription by the expression limited compatlbility. Thesynthetic resins forming resent invention not only formclear solutions when introduced into a'r films when thecoatin preadout and dried.

lacquer compositions but also yield entirely l his avoidance of *h'aziness or'cloudiness is referred-to in the present description and the. appended claims as a, compatibility characteristic.

, the synthetic resins.

' ample, as rosin,

compositions are I 1930. Serial No. 453,417.

ponent parts a polyhydrio alcohol-ester of a polybasic acid anda condensation product of a compound containing the carbonyl-group with a compound of a phenolic character, which resin exhibits the following cardinal properties: (1 solubility in drying oils with the capacity 0 forminga quick drying varnish; (2) miscibility with nitrocellulose solutions to the formation suitable for interior and exterior exposure; and (3) compatibility esters, such as cellulose acetate, in its various uses.

Synthetic resins containing esterified natural resin and synthetic resins of the phenolforn aldehydeand alkyd types and having the above-mentioned desirable characteristics, may, vention, be produced by forming one of the said synthetic resins in the presence of a natural esterifiable resin, and esterifyin the natural resin and. forming the other 0 the said synthetic first formed synthetic resin ture) The esterification of the natural resin may be a distinct step, or it mayoccur simultaneously with the production of either of Thus, I may forma phenol-formaldehyde resin in the y of a natural esterifiable resin, such, forex- (i. e., in the mixof a suitable esterification agent such as, for

instance, glycerin, bring about the esterifi cation of the natural resin by heating the mixture, and thereafter add to the mixture reactlng amounts ofa polybasic acid and a polyhydricalcohol. and heat the mixture to.

the formation therein of an alkyd resin. Or,

with other cellulose,

in accordance .with the present inresins in the presence ofthe.

presencemay carry hut the preparation of the phenol-formaldehyde resin in the presence of a durable lacquer i add an appropriate amount I have found, also, thatthe same resin prodthesizing the new resin which forms the subject matter of the present invention may be varied without departing from the invention.

The separate preparation of resin esters, of phenol-formaldehyde resin, and of alkyd resin being old per se, it will be understood, also, that the present invention admits of some latitudein the temperatures and proportions of reactants employed, and in the use of known equivalents as the reactants.

. It is not now known whether the components (esterified natural resin, phenolformaldehyde resin and alkyd resin) of the new synthetic resin are each present in the product as such or whether they have interacted to form new, more complex, resinous bodies. Without advancing any theory to account therefor, it may be noted,that the product has properties different from those of any of the components considered sepa rately, and that so far as is known the product is not separable by physical means into the aforesaidcomponents. For convenience in description, however, the product will be referred to hereinafter as being composed of the aforesaid components.

The invention will be more specifically described in connection with the following examples, which are merely illustrative of the process, the parts mentioned being parts by weight, and the temperatures being in centigrade degrees: 1 Ewwmple 1.250 parts of rosin and 25 parts of cresol, U. S. P., are melted together and 8 partsof paraformaldehyde are added at about 100 C. The action is allowed to proceed first for 1 hours at 120-125 C. with refluxing, and then for 1 hour at 220-225 C. with descending condenser to allow the formed water and any excess of reacting compounds to distillv ofi; 25 parts ofglycerin are then added, the temperature is raised to 270 C., and. the heating continued until the esterification iscompleted. At this point the reaction mixture appears to con sist of a fusion of C stage synthetic resin. of the phenol-formaldehyde type and the esterified natural resin. Tothe reaction mass allowed to .cool down to 180 'C., 25 parts of phthalic acid anhydride and 11 parts of glycerin are added, and the whole heated,preferably in an atmosphere of carbon dioxide, for 2 to 3 hours, to 220240 G. The heating is usualy discontinued when the reaction product shows an acidity of about 15-18. The resulting product is a clear, amber col-' ored resin, melting at about 101106 C. It

is completely soluble in the usual oxygencontaining organic solvents, such as alcohol and acetone, or mixtures of these solvents with hydrocarbons such as toluene, etc. It gives a clear solution when heated with drylng oils. To these solutions siccatives,- such as cobalt, manganese, and lead resinates, can be added, with the formation of a varnish drying in about four hours. This resin can be incorporated into nitro-cellulose and cellulose acetate solutions with the formation of clear, durable, lacquers.

It will be obvious to one skilled in this art that substitution of known equivalents may be resorted to without departing from the present invention. Thus, I may replace ore-- sol by another phenolic compound such as phenol itself; rosin by another natural esterifiable resin such, for instance, as copal; paraformaldeh'yde by another methylenecontaining hardening agent such as hexamethylene tetramine; formaldehyde, or the like; glycerin by glycol, or other polyhydric alcohol; and phthalic acid anhydride by another polybasic acid, or anhydride thereof, either of the aromatic series or of the alihatic series, of which diphenic acid, chlorenzoyl-benzoic acid, malic acid, and sue-- cinic acid are examples. 1

Example 2.-A resin is prepared as in Example 1, except that 60 parts of phthalic acid and 25 parts of glycerin are used in the last step. This resin is much harder (m. p. about 115 0.), and isespecially adapted for use in cellulose lacquers.

Example 51-65 parts of rosin, 30 parts of phthalic acid anhydride and 25 parts of glycerin are heated to 260 C., for 1 hours. After cooling, 50 parts of phenol and 17 parts of paraformaldehyde are added and the whole mass is heated to 230 C. for 1 hour. The resulting hard, medium-colored, resin is compatible with cellulose solutions and added and the heating continuedfor 1 hour.

The esterification of the/free acids of the resulting mass is then accomplished by addingv 21 partsof glycerin and heating for 2 hours at 250C. The acidity of the resulting resin is 11, and the lacquer prepared with it-accord ing to the formula below shows very good durability.'

' A varnish was prepared with resin pro- 'duced as in Example 1, as follows: 220 parts by weight of tung oil, 2O parts'of linseed oil, I

and 100 parts of the said resin were heated to 300 (1, and the heating continued until the properbonsistency was reached. The .product was then dlluted, to a 45% non-volatile content, with mineral s irits, and a solution of lead, manganese, an cobalt resinates was acting a polyhydric alcohol with ,ing in the presence added. The final varnish contained 03% cobalt, 03% manganese, and .6% lead. It showed a viscosity of G and a color of 4+ on the respective Gardner-Holdt scales.

The lacquer prepared with the said resin had the following composition:

25 parts trocellulose'.

25 parts toluene.

25 parts 50% solution of the resin in acetonefi 4 parts :dibutyl phthalate. It is to be understood that where in the second-32 oz.solution of niforegoing description and in the appended group consisting of alkyd resin and phenolformaldehyde resin.

2. Process which comprises forming a synthetic resin of the phenol-formaldehyde type in the presence of a natural esterfiable resin, and esterifying the natural resin and forming a synthetic resin of the alkyd type by rean organic polybasic acid in. the mixture.

3. Process which comprises reacting a phenol with a methylene-containing hardening agent in the presence of a rosin, heating the resulting mixture with a polyhydric alcohol, and reacting an organic polybasic acid with the polyhydric alcohol in the mixture.

4. Process which comprises reacting a phenol with a methylene-containing hardening agent in the presence of rosin and an organic polybasic acid, and heating the resulting mixture with a polyhydric alcohol whereby to esterify the rosin and the polybasic' acid.

5. The reaction product obtained by formof a natural esterifiable resin a synthetic resin of the group consisting of alkyd resin and phenol-aldehyde resin, and esterifying the .natural resin and forming in the mixture another synthetic resin of the aforesaid 'group, said reaction product being a complex resin having a melting point 7 above 100 C. and being'soluble in drying oils, miscible with nitrocellulose solutions and co mipatible with other celluloseesters to the formation ofclear lacquer compositions characterized by freedom from cloudiness when exposed in a thin film.

6. The reaction product obtained by forming in the presence of rosin a synthetic resin of the phenol-aldehyde type and esterifying the rosin and forming in the resulting mixture a synthetic resin of the alkyd type, said reaction product having a melting point above 100 C. and being completely soluble in oxygen-containing organic solvents and in drying oils, and compatible with nitrocellulose and cellulose acetate solutions to the formation of clear lacquer compositions characterized by freedom from cloudiness when exposed in a thin film.

In testimony whereof, I afiix my signature.

ELIAS BIELOUSS. 

